Round 11 of Buffalo Trace’s “Single Oak Project” experiment is here. In case you haven’t been with us for, oh, the last three years of this extravaganza, it’s designed to find the Holy Grail of just what is responsible for the perfect glass of whiskey.

This round looks primarily at warehouse type, once of the most ephemeral of the Single Oak Project variables. The company has two iconic types of warehouse, one (Warehouse K in this experiment) made of brick with wooden floors, and one (Warehouse L) made of brick with concrete floors. Wooden floors allow for better air flow from one level to another, but offers higher variation in climate from the bottom floors to the top ones. Concrete has OK air flow due to windows, but offers more consistency, with slower temperature changes. Neither warehouse is necessarily “better”… or is it? Wood grain and recipe (rye vs wheat) changed throughout this round, as well.

Overall, this is a very good batch, with a few exceptional whiskeys to be found in it — particularly Barrel #179 — and and almost none I wouldn’t at least cautiously recommend. Speaking of which, BT hasn’t released any additional news about which experimental release is in the lead, based on consumer reviews.

Buffalo Trace Distillery Single Oak Project Barrel #23 – A good slug of spice on the nose… once you push through a bit of heat. Beyond, you’ll find an impressive spirit, filled with vanilla, some cocoa and coffee bean notes, and a soothing woodiness to back it up. Long and sweet on the finish, it’s a beautiful sipper that belies its rustic nose. A top pick of this series. A- (rye, 105 entry proof, level 6 seasoning, tight grain, concrete ricks, #4 char, top half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #83 – Hard to parse on the nose, the aromas are closed off but heaviest on basic wood notes. The body is on the simple side — sweet, melted caramels, a touch of raisin. Completely agreeable. B+ (rye, 105 entry proof, level 6 seasoning, average grain, wooden ricks, #4 char, top half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #87 – Big nose, offering menthol character with a lot of heat… and a touch of chocolate. The body is surprisingly rich and creamy, with sultry cinnamon and coffee bean notes, and a kind of cafe au lait finish. Surprising and unusual, with its powerful nose and exotic body. I like it quite a bit. A- (rye, 105 entry proof, level 6 seasoning, average grain, concrete ricks, #4 char, top half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #115 – Heavy wood on the nose, but the sweetness on the body offers respite, and balance. This is one of this project’s few whiskeys with a clear grain-and-popcorn character, indicating it could stand a few more years in barrel… maybe more. Curious raspberry tea notes on the finish add fun. A- (wheat, 105 entry proof, level 6 seasoning, average grain, wooden ricks, #4 char, top half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #147 – Tightly wound. This is at first a tougher bourbon, bound up with oak staves and sawdust. But the finish comes along with a curious cookie character — pecan sandies, anyone? — that adds nuance and a touch of intrigue. B (rye, 105 entry proof, level 6 seasoning, coarse grain, wooden ricks, #4 char, top half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #151 – Pure wood on the nose, with some cinnamon lacing, perhaps. The body is sweet at first, giving way to a hefty wood character that builds and builds to a slightly astringent finish. B (rye, 105 entry proof, level 6 seasoning, coarse grain, concrete ricks, #4 char, top half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #179 – Classically structured. Deep wood impregnated with vanilla on both the nose and the palate. The body is velvety, the finish long and chocolaty. Interesting notes of marshmallow and licorice here and there. Lots to explore. An easy winner for this installment — and the series as a whole. A (wheat, 105 entry proof, level 6 seasoning, coarse grain, wooden ricks, #4 char, top half of tree)

Buffalo Trace Distillery Single Oak Project Barrel #183 – Ripe banana meets wood on the nose. On the tongue: Incredibly sweet, which makes it incredibly drinkable, but almost puts it on par with a Cognac over a traditional Bourbon. Would love to see a touch more austerity from this, but could easily sip on it for days. A- (wheat, 105 entry proof, level 6 seasoning, coarse grain, concrete ricks, #4 char, top half of tree)